Delta Z-Score Indicator: Formula, Settings and How to Read It
Delta Z-Score expresses each bar's delta in standard deviations from its own recent average, over a rolling window of the last N bars including the current one. A reading of +2 places this bar's delta two standard deviations above the mean delta of that window.
Senzoukria · Indicators · Updated September 2026
Delta Z-Score ships with the Senzoukria desktop app, in the Delta group of the indicator catalogue. It is drawn in its own panel below the chart.
What Delta Z-Score measures
The standard deviation is the population form, dividing by N rather than N−1, the same convention as the Bollinger Bands in this catalog and the one used by TradingView and ATAS. The window rolls continuously and is not reset at the session open, so it crosses session boundaries like any other moving statistic. Two cases produce no value instead of a number: warm-up, before N bars exist, and a perfectly flat window whose standard deviation is zero, where the z-score is undefined and a printed zero would be wrong. The series is therefore relative by construction: it states how unusual this bar's delta is against its own recent history, not how large it is.
The formula, as implemented
This is not a description of how the indicator is usually defined elsewhere — it is what the shipped code computes, documented next to the implementation:
Z-score du delta : (delta − μ_N) / σ_N, fenêtre des N dernières barres INCLUANT la courante ; σ = écart-type de POPULATION (÷N, pas ÷(N−1) — même convention que les Bollinger du catalogue, parité TradingView/ATAS). Warm-up (< N barres) → null ; σ = 0 (fenêtre plate) → null (z indéfini, jamais « 0 »). Oscillateur CONTINU — pas de reset session. Défaut N=20, la fenêtre statistique standard des BB.
How to read it
- A reading near zero means the bar's delta is typical for the window. It does not mean delta was near zero: in a strongly one-sided window the mean is displaced, and an ordinary positive delta can read near zero.
- Readings beyond ±2 mark bars sitting outside the bulk of the recent distribution; check the raw delta at the same time to see whether that is a large number or merely an unusual one.
- Comparing readings across instruments works as a comparison of unusualness, and only while the windows cover comparable activity regimes.
- A run of same-signed extremes describes a stretch in which one side kept arriving harder than its own recent norm.
- Missing values at the start of a chart, or after a completely flat stretch, are undefined. Do not read them as neutrality.
Parameters and defaults
Period defaults to 20, the window the Bollinger convention uses, and accepts 2 to 500. The arithmetic bounds what a short window can show: with a population standard deviation over N values, the absolute z-score cannot exceed (N−1)/√N, so a period below 6 never reaches ±2 at all. A long period gives a stable reference but reacts slowly and can cover two different activity regimes inside one window. Color, default #ab47bc, changes only how the line is drawn.
| Parameter | Type | Default | Range |
|---|---|---|---|
| Period | number | 20 | 2 – 500 |
What it does not show
A z-score answers whether a delta is unusual for its window, never whether it is large in contracts: in a quiet stretch the standard deviation shrinks and an ordinary delta can read as extreme. With no session reset, a window straddling the overnight break blends two very different activity regimes into one mean and one standard deviation. The measure also inherits every property of the delta feeding it, including how the aggressor side was determined upstream. As a normalization layer it adds nothing about price, volume or resting liquidity.
Using it in Senzoukria
Add it from the Indicators panel of any footprint chart or candle chart. It runs on futures data from Rithmic or Databento and on crypto pairs from Binance and Bybit, on the same engine — the calculation does not change with the venue, only the data feeding it does. Market data subscriptions are billed by the provider, separately from the app.
Related indicators
- Delta min/max — Delta
- Price/Delta Divergence — Delta
- Delta % Histogram — Delta
- Max Delta — Delta
- Min Delta — Delta
- Trades Delta — Delta
See the full indicator library, or start with the order flow guide if you are new to reading aggression, delta and absorption.
Frequently asked questions
- What does a delta z-score of 2 mean?
- The current bar's delta sits two standard deviations above the average delta of the window, the last 20 bars by default. It states how unusual the value is next to recent bars, not its size in contracts. The same reading on a quiet instrument and on a busy one can correspond to very different absolute deltas.
- Why is my Delta Z-Score blank at the start of the chart?
- A full window is needed before a value exists, so the first N−1 bars have none, 19 bars with the default period of 20. A blank also appears whenever the window is perfectly flat, because a standard deviation of zero leaves the z-score undefined. These blanks are deliberately not drawn as zero.
- Does a delta z-score reset at the session open?
- Not in this implementation. It is a continuous rolling oscillator with no session anchor, so the window keeps its earlier bars across the session boundary and the first bars of a session are measured partly against the previous one. Read it as a relative-activity gauge, and take any measure that must restart each session from a session-anchored series instead.